Content reproduction system, content reproduction apparatus, and content reproduction method

ABSTRACT

The present invention provides a content reproduction system that can continue reproduction of a plurality of content even if a part of content is unreproducible. The content reproduction system includes a content storage apparatus including a content storage section that stores a plurality of content whose reproduction order has previously been specified based on reproduction order information, and a content reproduction apparatus including a communication section that communicates with the content storage apparatus, a request section that requests the content storage apparatus to transmit content stored in the content storage section in the order according to the reproduction order information, and a reproduction section that reproduces the content, wherein when content that the request section has requested from the content storage apparatus is unreproducible, the request section requests the content storage apparatus to transmit content which is listed as content to be reproduced subsequent to the unreproducible content in the reproduction order information.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of prior application Ser. No.12/793,986, filed Jun. 4, 2010, which is a continuation of priorapplication Ser. No. 11/351,027, filed Feb. 9, 2006, which claims thepriority benefit of Japanese patent application number 2005-033406,filed in the Japanese Patent Office on Feb. 9, 2005, each of which ishereby incorporated by reference to the maximum extent allowable by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a content reproduction system, acontent reproduction apparatus, and a content reproduction method thatsequentially reproduce a plurality of content.

2. Description of the Related Art

In the past, an optical recording medium such as CD (Compact Disc) or MD(Mini Disc™) has been available. Not only music content, but alsomanagement information of the music content is recorded on such anoptical recording medium. The management information includes items ofstart/end address of content, title of a recording medium, title ofmusic, artist name, and the like. Information related to reproductionorder is not recorded in TOC (Table Of Contents) which is managementinformation of a CD. In the CD, content is reproduced in the order thatit has been recorded on the CD. On the other hand, a management tablethat manages the reproduction order of the content is recorded in UTOC(User Table Of Contents) which is management information of an MD. Themanagement table describes a recording position of the content and amusic number of the content corresponding to the recording position. Themanagement table can be rewritten by a user side. The MD cansequentially reproduce content in a user-specified order (refer to, forexample, Jpn. Pat. Appln. Laid-Open Publication No. 2003-36654).

In recent years, a content reproduction system that connects a serverand a client by a network and allows the client to reproduce contentstored in the server has existed. In such a content reproduction system,reproduction order information is stored in the server. The reproductionorder information includes items of album list, playlist, reproductionorder list classified by artist's name, and the like. When reproducingcontent in the content reproduction system in a sequential manner, auser selects desired reproduction order information such as album listor playlist. The client outputs a content transmission request to theserver according to received reproduction order information. The servertransmits content in response to the transmission request issued by theclient.

SUMMARY OF THE INVENTION

In recent years, a content format has been diversified. In order toreproduce content of various formats, a decoder that converts contentinto a desired reproduction signal is necessary. For example, an MP3(MPEG Audio layer 3) decoder is necessary in order to reproduce MP3music content. When a client in a conventional system receives contentof a format that the client cannot reproduce, the client determines thatthe content is unreproducible and stops reproduction operation afterreproducing reproducible portion.

The user instructs the client to sequentially reproduce a plurality ofmusic pieces in units of album or playlist. Although the user hasdesignated a given album or playlist, sequential reproduction of allmusic pieces is forced to stop due to existence of only oneunreproducible music piece in the album. Accordingly, the user needs toperform additional operation for the client for the reproduction ofremaining music pieces.

The present invention has been made in view of the above problem, and itis desirable to provide a content reproduction system and a contentreproduction apparatus capable of continuing reproduction operation evenif there is any unreproducible content in a plurality of content to bereproduced in a sequential manner.

According to the present invention, there is provided a contentreproduction system including: a content storage apparatus including acontent storage means for storing a plurality of content whosereproduction order has previously been specified based on reproductionorder information; and a content reproduction apparatus including: acommunication means for communicating with the content storageapparatus; a request means for requesting the content storage apparatusto transmit content stored in the content storage means in the orderaccording to the reproduction order information; and a reproductionmeans for reproducing the content, wherein when content that the requestmeans has requested from the content storage apparatus isunreproducible, the request means requests the content storage apparatusto transmit content which is listed as content to be reproducedsubsequent to the unreproducible content in the reproduction orderinformation.

According to the present invention, there is provided a contentreproduction apparatus including: a reproduction order informationacquisition means for acquiring the reproduction order informationrelated to content; a content acquisition means for acquiring content inthe order according to the reproduction order information; areproduction means for reproducing the content, wherein when the contentacquired by the content acquisition means is unreproducible, contentwhich is listed as content to be reproduced subsequent to theunreproducible content in the reproduction order information is acquiredand reproduced.

According to the present invention, there is provided a contentreproduction method including: a reproduction order informationacquisition step of acquiring the reproduction order informationdescribing the reproduction order of content; a readout step of readingout content stored in content storage means in the order according tothe reproduction order information; a subsequent content readout stepof, when content listed in the reproduction order information isunreproducible, reading out content which is listed in the reproductionorder information as content subsequent to unreproducible content; andreproduction step of reproducing the readout content.

In the case where content to be reproduced is unreproducible, thecontent reproduction system according to the present invention requeststhe content storage apparatus to transmit content which is listed in thereproduction order information as content to be reproduced subsequent tothe unreproducible content. Then, when the requested content isreproducible, the system uses the reproduction means to reproduce thecontent. Thus, even if unreproducible content exists in the reproductionorder information, it is possible to continue sequential reproductionusing only reproducible content.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a contentreproduction system;

FIG. 2 is a view showing an example of a reproduction list;

FIG. 3 is a view schematically showing processing performed by a musiccontent delivery section;

FIGS. 4A and 4B views showing operations of a reception ring buffer;

FIG. 5 is a view showing a display example for notifying a user thatcontent cannot be reproduced;

FIG. 6 is a flowchart showing operation of a client; and

FIG. 7 is a block diagram showing a configuration of a CD playeraccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A content reproduction system 1 according to the present invention willbe described below with reference to the accompanying drawings. FIG. 1shows a configuration of the content reproduction system 1. The contentreproduction system 1 includes a server 2 that stores content, a client3 that reproduces the content, and a switching hub 4 that relayscommunication between the server 2 and the client 3. The abovecomponents in the content reproduction system 1 are connected to eachother by LAN (Local Area Network) and perform communication according toTCP/IP (Transport Protocol/Internet Protocol). The content reproductionsystem 1 may adopt another configuration or communication method.

The server 2 includes a content storage section 21 that stores musiccontent, a reproduction list storage section 22 that stores reproductionlists of the music content, a communication section 23 that performscommunication with the client 3, a music content delivery section 24that performs a music content delivery service, and a system controller25 that controls the entire server 2.

The content storage section 21 stores music content. The reproductionlist storage section 22 stores a reproduction list that indicates thereproduction order of the music content. As shown in FIG. 2, thereproduction list describes items of music content name, content type(content format), sampling frequency, channel number, bit number,reproduction time length of music content, URL of music content,reproduction order of content, and the like. The reproduction list canbe classified into album list, playlist, artist list, and the like. Thealbum list is a reproduction list of music content included in a givenalbum. The playlist is a user-created reproduction list of musiccontent. The artist list is a reproduction list of music content of asingle artist.

The music content delivery section 24 delivers music content stored inthe content storage section 21 to the client 3. FIG. 3 schematicallyshows processing performed by the music content delivery section 24. Themusic content delivery section 24 firstly reads out a reproduction listfrom the reproduction list storage section 22. The read out reproductionlist is transmitted to the client 3 through the communication section 23(I). The reproduction list describes the URLs of the music content to bereproduced. The client 3 selects music content to be reproduced from thereproduction list and transmits the URL of the selected music content tothe server 2 (II). The music content delivery section 24 reads out musiccontent corresponding to the URL received from the client 3 andtransmits the readout music content to the client 3 (III).

The client 3 includes a communication section 31 that performscommunication with the server 2, a content request section 32 thatrequests the server 2 to transmit required data thereto, a receptionring buffer 33 that temporarily stores the music content input from theserver 2, a converter 34 that converts the music content transmittedfrom the server 2 from a digital signal into an analog signal, anamplifier 35 that outputs the analog music signal to a speaker 36, aninput section 37 that receives user's operation, such as a key or remotecontroller, and a display section 38.

The client 3 receives music content from the server 2, converts thereceived music content from a digital signal to an analog signal, andreproduces the analog music signal through the speaker 36. Music contentof a PCM format transmitted from the server 2 is stored in the receptionring buffer 33. At the time point when a given amount of music contentis stored in the reception ring buffer 33, the music content is outputto the converter 34. As a result, the music content of a given albumlist is sequentially reproduced without interruption between musicpieces, being suitable for reproduction of a live album. The converter34 converts a digital music signal into an analog music signal andoutputs the analog music signal to the amplifier 35. The analog musicsignal is amplified by the amplifier 35 and thereby the music is outputthrough the speaker 36.

FIGS. 4A and 4B show operations of the reception ring buffer 33. A writepointer and a read pointer are set in the reception ring buffer 33. FIG.4A shows reading operation. The data reading operation is performed atregular intervals and music content is output to the converter 34 at aregular speed. The area from which the music content has been read outaccording to the read pointer becomes a data writable area. FIG. 4Bshows writing operation. In the writing operation, the write pointermoves in the data writable area and, when the data writable area becomessmall, the reception ring buffer stops reception operation and waitsuntil the reading operation has advanced.

The content request section 32 requests the server 2 to transmit musiccontent thereto. The reproduction order of the content is described inthe reproduction list. Upon receiving a first track, the content requestsection 32 requests the server 2 to transmit a second track in the listthereto. The reception ring buffer 33 writes the received second trackon the area following the end of the first track. After completion ofthe reception of the second track, the content request section 32requests the server 2 to transmit a third track in the list thereto. Ifthere is no track to be reproduced next, the content request section 32does not issue additional transmission request.

When the music content described in a reproduction list isunreproducible, the content request section 32 stops reproduction of theunreproducible music content and requests the server 2 to transmit thenext music content.

When target music content is not stored in the URL listed in thereproduction list, the content request section 32 determines that thismusic content is unreproducible. The absence of the music content occursdue to, for example, disconnect between the URL listed in thereproduction list and actual storage area of the music content. There isa time lag between reception of a reproduction list and reception ofmusic content. If given music content included in a reproduction list isdeleted or moved after transmission of the reproduction list to theclient, the target content has disappeared from the corresponding URL inthe reproduction list at the reception time of the music content.

If there is no reproducible music content, the content request section32 notifies the user that the music content to be reproduced next isunreproducible after completing reproduction of the current musiccontent. A message saying, “Can't play” is displayed in the displaysection 38 of FIG. 5 for notifying the user that the music content to bereproduced next is unreproducible. At this time, the massage may beblinked, or the title of the unreproducible music may be displayedtogether with the message. The content request section 32 determines theend of the music content based on the reproduction time length of themusic content. The content request section 32 compares the storageamount of the music content in the reception ring buffer 33 and residualreproduction time of the currently reproduced track. The reception ringbuffer 33 outputs the entire currently reproduced music content to theconverter 34 based on a result of the comparison.

Then, the content request section 32 mutes audio output, reads out theURL of a track following the reproduced music content, and transmits theURL to the server 2. At the time point when a given amount of musiccontent is stored in the reception ring buffer 33, the content requestsection 32 releases the mute. The reception ring buffer 33 outputs thestored music content to the converter 34.

The content request section 32 determines that music content of a formatthat the client 3 cannot reproduce is unreproducible content. The client3, which is not provided with a decoder for expanding a compressed data,can only reproduce music content of a PCM format. The content requestsection 32 therefore determines that music content of a format otherthan a PCM is unreproducible content.

The format of the music content can be determined from the reproductionlist. The format of the content is listed in the content type of thereproduction list of FIG. 2. The content request section 32 refers tothe reproduction list and, if the content type is not a PCM format,displays in the display section 38 that it is impossible to reproducemusic content, followed by request of the next music content.

Further, the format of the music content can be determined from a fileheader or the like of received music content. The format of the musiccontent is included in the file header. When determining that the typeof received music content is not a PCM format, the content requestsection 32 displays in the display section 38 that it is impossible toreproduce music content, followed by request of the next music content.

As described above, the format of the music content is determined notonly from the content type of the reproduction list, but also fromreceived music content itself. Thus, if the description of the contenttype in the reproduction list is wrong, it is possible to stopreproduction of unreproducible music content and issue a transmissionrequest of the next music content.

In the case where there exist a reproducible part and unreproduciblepart in single music content, the content request section 32 firstlyreproduces the reproducible part and, then, displays in the displaysection 38 that reproduction of the music content that is beingreproduced has become impossible. After that, the content requestsection 32 reads out the URL of the music content following the onewhose reproduction has been stopped and transmits the read out URL tothe server 2.

The content request section 32 waits for network recovery if it cannotreceive content due to a communication error. When the communicationerror continues for a predetermine time, the content request section 32allows the display section 38 to display that content cannot be acquireddue to a communication error.

Operation of the client 3 will next be described with reference to aflowchart of FIG. 6. When the music content to be reproduced next is theone of an unreproducible format, the content request section 32 comparesthe residual reproduction time of the currently reproduced track andstorage amount of the music content in the reception ring buffer 33.When determining, based on the comparison, that the reception ringbuffer 33 stores the entire currently reproduced music content (step S1;YES), the content request section 32 allows the reception ring buffer 33to output the entire currently reproduced music content to the converter34 (step S2). On the other hand, when determining that all the currentlyreproduced music content is not stored in the reception ring buffer 33(step S1; NO), the content request section 32 allows the reception ringbuffer 33 to output a reproducible portion of the currently reproducedmusic content to the converter 34 (step S3).

The content request section 32 allows the display section 38 to displaya message for notifying a user that music content is unreproducible(step S4). At the same time, the content request section 32 reads out,from the reproduction list, the URL of the music content following theunreproducible music content and outputs the read out URL to the server2. Upon receiving the music content following the unreproducible musiccontent from the server 2 (step S5), the content request section 32waits until a certain amount of the music content is stored in thereception ring buffer 33 (step S6; NO). When a certain amount of themusic content is stored (step S6; YES), the content request section 32allows the reception ring buffer 33 to output the stored music contentto the converter 34 (step S7). The music content output from theconverter 34 is amplified by the amplifier 35 and reproduced through thespeaker 36 as music.

As described above, when the reproduction list describing thereproduction order of music content includes music content of anunreproducible format, the content reproduction system 1 according tothe present invention skips the unreproducible music content andreproduces the next track. Further, in the case where music contentbeing reproduced becomes unreproducible in the middle of thereproduction, the content reproduction system 1 skips the unreproduciblepart after reproducing up to the reproducible position and reproducesthe next track. While the reproduction operation is interrupted due toexistence of the unreproducible music content in a conventional system,the content reproduction system 1 is capable of continuing reproductionoperation even if there is any unreproducible content in thereproduction list.

A CD (Compact Disc) player 5 according to the present invention willnext be described. FIG. 7 is a block diagram showing a configuration ofthe CD player 5. The CD player 5 includes a driver 51 thatdrives/rotates a CD, a pickup section 52 that reads out opticalinformation from the CD, a signal processing section 53 that converts anelectrical signal read out from the CD into a reproduction signal, a TOCmemory 54 that stores TOC (Table Of Contents) information, an amplifier55 that amplifies the reproduction signal, a speaker 56 through whichthe reproduction signal is reproduced as music, a display section 57,and a sequential reproduction processing section 58 that sequentiallyreproduces music content recorded in the CD.

Control information called TOC is recorded in the lead-in area of a CD.The TOC includes start/end address of music content, title of musiccontent, artist name, and the like. The information recorded in the TOCis loaded into the TOC memory 54.

When there is something wrong with currently reproduced music contentand the subsequent music content, the sequential reproduction processingsection 58 reads out from a memory the start address of the musiccontent following the defective music content and starts reproduction ofthe readout music content. Thus, even if there is something wrong withthe reproduction of music content, it is possible to continuereproduction of music.

The function corresponding to the sequential reproduction processingsection 58 is applicable not only to the CD player, but also to an HDDplayer or MD (Mini Disc™) player.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alternations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A content reproduction apparatus for reproducing content, the contentreproduction apparatus comprising: at least one processor to: request acontent storage apparatus to transmit a plurality of content itemsselected from a reproduction list stored on the content storageapparatus to the content reproduction apparatus, wherein an order of theplurality of content items is specified based on reproduction orderinformation; receive from the content storage apparatus at least onefirst content item from the plurality of content items; and when it isdetermined that the at least one first content item is unreproducible bythe content reproduction apparatus, request the content storageapparatus to transmit at least one second content item from theplurality of content items, wherein the at least one second content itemis listed in the reproduction order information as a content item to bereproduced subsequent to the at least one first content item.
 2. Thecontent reproduction apparatus of claim 1, wherein: the at least oneprocessor requests the content storage apparatus to transmit theplurality of content items to the content reproduction apparatus basedon user input.
 3. The content reproduction apparatus of claim 1,wherein: the at least one first content item is determined to beunreproducible by the content reproduction apparatus based on a formatof the at least one first content item.
 4. The content reproductionapparatus of claim 3, wherein: the at least one first content item isdetermined to be unreproducible by the content reproduction apparatuswhen the format of the at least one first content item is different froma format that is recognized by the content reproduction apparatus. 5.The content reproduction apparatus of claim 3, wherein: the format ofthe at least one first content item is determined based on informationin a header of the at least one first content item.
 6. The contentreproduction apparatus of claim 4, wherein: the format of content thatis recognized by the content reproduction apparatus comprises at leastone selected from the group consisting of an MP3 format and a PCMformat.
 7. The content reproduction apparatus of claim 1, wherein: thereproduction list comprises a location of the at least one first contentitem in a storage; and the at least one first content item is determinedto be unreproducible by the content reproduction apparatus when thelocation does not contain the at least one first content item.
 8. Thecontent reproduction apparatus of claim 7, wherein: the location of theat least one first content item comprises a URL of the at least onefirst content item.
 9. The content reproduction apparatus of claim 1,wherein: when it is determined that the at least one first content itemis unreproducible by the content reproduction apparatus, the at leastone processor provides an indication to a user that the at least onefirst content item is unreproducible.
 10. A method for reproducing aplurality of content items, the method comprising: with at least oneprocessor: requesting an external apparatus to transmit a plurality ofmusic content items selected from a reproduction list stored in theexternal apparatus, wherein the plurality of music content items arespecified in an item list comprising identification informationidentifying the plurality of music content items and specifying alocation of each of the plurality of music content items in a storage;receiving, from the external apparatus, at least one first music contentitem from the plurality of music content items; during reproduction ofthe at least one first music content item, determining whether at leastone second music content item from the plurality of music content itemslisted in the item list as a music content item to be reproducedsubsequent to the at least one first music content item isunreproducible; and when it is determined that the at least one secondcontent music item is unreproducible, completing the reproduction of theat least one first music content item, and requesting from the externalapparatus at least one third music content item from the plurality ofmusic content items, wherein the at least one third music content itemis listed in the item list as a music content item to be reproducedsubsequent to the at least one second music content item.
 11. The methodof claim 10, wherein the at least one second music content item isdetermined to be unreproducible based on a format of the at least onesecond music content item.
 12. The method of claim 10, wherein the atleast one second music content item is determined to be unreproduciblewhen a location of the at least one second music content item in thestorage specified in the item list does not contain the at least onesecond music content item.
 13. The method of claim 10, furthercomprising, when it is determined that the at least one second musiccontent item is unreproducible, providing an indication on a displaythat the at least one second music content item is unreproducible. 14.The method of claim 13, wherein the indication is provided at leastpartially concurrently with requesting from the storage the at least onethird music content item.
 15. The method of claim 13, wherein providingthe indication comprises displaying text information on a display.
 16. Acontent reproduction apparatus adapted to communicate with an externalapparatus, the content reproduction apparatus comprising: a contentrequest section to: request the external apparatus to transmit aplurality of content items selected from a reproduction list stored inthe external apparatus to the content reproduction apparatus, whereinthe plurality of content items are specified in an item list comprisingidentification information identifying the plurality of content itemsand specifying a location of each of the plurality of content items in astorage; receive, from the external apparatus, at least one firstcontent item from the plurality of content items; determine whether atleast a portion of the at least one first content item is unreproducibleby the content reproduction apparatus; and a content reproductionsection to: when it is determined that the at least a portion of the atleast one first content item is unreproducible by the contentreproduction apparatus, reproduce another portion of the at least onecontent item that is reproducible by the content reproduction apparatus,wherein: when it is determined that the at least a portion of the atleast one first content item is unreproducible by the contentreproduction apparatus, the content request section is adapted torequest the external apparatus to transmit at least one second contentitem from the plurality of content items that is listed in the item listas a content item to be reproduced subsequent to the at least one firstcontent item.
 17. The content reproduction apparatus of claim 16,wherein: when it is determined that the at least a portion of the atleast one first content item is unreproducible by the contentreproduction apparatus, the content request section provides anindication on a display that the at least a portion of the at least onefirst content item is unreproducible.
 18. The content reproductionapparatus of claim 17, wherein: the indication comprises a title of theat least one first content item.
 19. The content reproduction apparatusof claim 16, wherein: the item list is received from the externalapparatus via a local area network.
 20. The content reproductionapparatus of claim 16, wherein: the item list comprises at least oneselected from the group consisting of an album list, a playlist and anartist list, and wherein the plurality of content items comprise aplurality of music pieces.